1. Field of the Invention
The present invention relates to a method for the differential rendering of portal pages on the server and refreshing them on the client. In particular the inventive method relates to the interaction between a server and a browser of a client.
2. Description of the Related Art
A conventional portal page aggregation system usually transfers the complete portal page. In particular, the complete markup, which corresponds with the visual representation of the portal page, is sent as a markup document from the server to the browser of the client. The markup includes all portlets and navigation elements.
There are two main disadvantages with using this approach: First, the server-side processing time for rendering the page is slow since the markup of each page element has to be requested. Second, since the markup document is very large, transfer of the markup from the server to the client results in a high data flow between server and browser.
According to an alternative conventional method, the complete page is only downloaded from the server to the browser the first time the portal page is accessed. Subsequently, the client sends separate requests for only those parts of the portal page that have changed via so-called client side includes (CSI). Accordingly the server sends the markup for each of these parts in a separate response to the browser.
However, this approach also has a major drawback: Refreshing individual page parts does not work well because the browser is not able to always determine those parts of the portal page correctly. This is a result of the browser not knowing the portal-specific semantics of the received user events. This is especially problematic if several portlets are communicatively linked, i.e. when a click into one portlet has an effect on another portlet.